The present invention relates to a circuit arrangement comprising at least one power component and a drive circuit for the power component.
Circuit arrangements comprising power components, such as power transistors for example, are in widespread use. Examples thereof are switching converters in which a power transistor is driven by a drive circuit in a clocked manner for regulating the power consumption of the converter, or half-bridge circuits which have two power transistors and which are used for example for driving motors or in lamp ballasts.
Particularly when power components are used for complex switching and regulating operations, such as occur for example in switching converters, in motor drive circuits or in lamp ballasts, complicated drive circuits for driving the power components are required which, in addition to a control function, can also fulfill a protection function for the power component.
Said drive circuits can be integrated together with the power component in a common semiconductor chip. One example of a circuit which is integrated in a chip and comprises both a high-voltage power transistor and the drive circuit thereof is the integrated switched-mode power supply control circuit of the TOP232-234 type from the company Power Integrations, which is described in the data sheet “TOP232-234 TOPSwitch®-FX Family”, July 2001. In the case of this circuit, a high-voltage MOSFET, a pulse width modulator for driving the MOSFET and error protection circuits for the MOSFET are integrated, inter alia, as a CMOS circuit in a single chip.
So-called BCD technology (BCD=Bipolar, CMOS, DMOS), which is described, for example, in Zitta et al.: “SPT4/90V—A Voltage Derivative of the Smart Power Technology opens the Door to the 42V PowerNet”, Infineon Technologies AG, Munich, makes it possible to integrate not only a power component but also complex control circuits with CMOS components and bipolar components in a single semiconductor chip.
A further method for integrating a power component and a drive circuit in a common semiconductor chip is described in US 2002/0041003 A1.
Methods for integrating a power component and a drive circuit for the power component in a single chip are complicated and cost-intensive since a multiplicity of process steps are required in order to jointly integrate the power component and the drive or logic components, which differ significantly with regard to their dielectric strength. While the dielectric strength of CMOS components in the drive circuit, depending on the supply voltage, must be between 3.3V and 5V, even just 1.1V in future technologies, considerably higher dielectric strengths are demanded for power components. If only because of these different requirements made of the dielectric strength, logic components, for example CMOS transistors, of the drive circuit and the power component, for example a power MOSFET, cannot be produced by means of common method steps. Therefore, separate method steps are required for realizing the logic components and for realizing the at least one power component, which increases the number of masking and deposition steps and thus makes the production method more expensive. Furthermore, when integrating logic and power components in a chip, it is often necessary to make a compromise between the desired properties of the power component and the desired properties of the logic components.
In order to avoid the problems that occur in single-chip circuits, it is known to integrate the power component and the drive circuit thereof in separate chips and to arrange these two chips, if appropriate, in a common chip housing. Examples of such circuits are the integrated circuits of the CoolSET® family from Infineon Technologies AG, Munich. These circuits each have a power MOSFET and the drive circuit thereof, which are integrated in different chips and arranged in a common housing.
A two-chip circuit comprising a power transistor and a drive circuit is also embodied by the switched-mode power supply control circuit of the TEA1208T type from Philips Semiconductors. In this circuit, a power transistor is integrated in one chip by means of a high-voltage SOI process, while the drive circuit thereof is integrated in a second chip. In this case, the drive circuit is integrated in the second chip using a so-called BICMOS process (BICMOS=Bipolar CMOS) and comprises both bipolar components and CMOS components. However, BICMOS processes are expensive and complicated.
It would therefore be advantageous to provide a circuit arrangement comprising at least one power component and a drive circuit or protection circuit for the at least one power component which is optimized with regard to the desired properties of the power component and of the components of the drive circuit and also with regard to the production costs.